Effects of Including Flax in Creep Feed on Performance, Health, and Carcass Characteristics: Progress Report

T. D. Maddock,T. C. Gilbery, and G. P. Lardy,NDSU Animal and Range Sciences Department

B. Kreft, NDSU Central Grasslands Research Extension Center

Introduction

Flax is an oilseed and a source of the omega-3 (–3) fatty acid alpha-linolenic acid (ALA). Flax contains approximately 18-20% ALA on a dry matter basis. Omega-3 fatty acids have been implicated in the reduction and prevention of cancers and cardiovascular disease, along with being immunomodulatory and anti-inflammatory. Recent work on including flax in beef cattle feedlot diets suggests that flax increases immune response in receiving heifers and improves performance and feed efficiency (Farran et al., 2002). Additionally, feeding flax is currently being investigated as a way to enrich beef with –3 fatty acids as a way to deliver them into the human food chain. Maddock et al. (2003) reported an increase in ALA levels in beef from steers that were fed finishing diets that included 3% or 6% (dry basis) flax when compared to traditional barley or corn based finishing diets.

Creep feeding is the management practice of providing supplemental feed to calves while they are still nursing. Creep feeding is typically used to increase weaning weights and acclimate calves to concentrate (grain) diets. In addition, creep feeding can be used to reduce stress on pastures by reducing energy requirements of lactating cows (Myer et al., 1999). However, the impact of creep feeding on the ultimate quality and palatability of meat has not been determined. Other studies (Fluharty et al., 2000) have investigated time of weaning effects on carcass characteristics. Generally, the younger a calf is started on high concentrate (grain) diets, the higher the ratings for tenderness and overall palatability of meat.

Using these data, a study was designed to investigate the effects of adding flax to creep feed on nursing calf performance and subsequent feedlot performance and health. Additionally, calves will be finished so quality grades, yield grades and fresh beef palatability can be measured, along with fatty acid analysis to determine the –3 content of the beef from these calves.

Materials and Methods

 At Central Grasslands Research Extension Center ninety-six cow-calf (steer) pairs were stratified by cow age and calf weight and then allotted to one of 12 pastures (8 pairs per pasture) in August 2003. Each pasture was assigned randomly one of four treatments (3 pastures/treatment) in a completely randomized design. Treatments were 1) a no creep control, 2) a wheat midds and soy hulls based creep feed, 3) creep feed that includes flax at 12.5% of DM, 4) creep feed that includes flax at 25% of DM. Creep feed composition is presented in Table 1. During the initial 21 days of the feeding period, the control creep feed was offered ad libitum to adjust calves to feed and creep feeders. Following this adjustment, calves were switched to treatment diets, which were offered ad libitum for 37 days. Creep feed intake was measured once weekly. On October 7, calves were weighed and weaned and are currently on a backgrounding diet at CGREC, after which they will be switched to a finishing diet. During the backgrounding and finishing periods, cattle will be observed for health and performance will be recorded. When it is visually determined that 60% of the cattle should grade USDA choice, they will be harvested at a commercial abattoir where carcass data will be collected by trained evaluators. Meat samples will be collected and transported to the North Dakota State University meats laboratory and used for mechanical analyses of palatability and sensory panel evaluation of tenderness, juiciness, flavor desirability and flavor intensity. Samples will also be tested for fat content and fatty acid composition.

Results and Conclusions

Results available at this time (Table 2) include cow and calf performance and feed intake. No performance or intake differences (P > 0.10) were noted for treatment or when comparing creep fed calves to the no creep control. Additionally, no differences were found when comparing 12.5% flax creep feed to the 25% flax creep feed.